MTL - Dark Demon Warlock - Chapter 3 fallen devil

A swordsman hailed as the strongest has reached his end, and was reborn as an elven girl.

This is the story of the swordsman only knowing how to kill in his past life aiming to be the best healer as a girl.

In the final battle against a monstrous entity with his teammates, the strongest swordsman, the Hero’s mentor and the only one in their party incapable of magic yet the most skilled with the sword, sacrificed his life to end the battle once and for all. Reincarnated as an elf girl, the strongest swordsman decided to live a different life from his blood-stained past and pursue the magic that he has never used before.

As a girl, she apprenticed under the old potion maker and healer of the village to be like someone she had admired in her previous life while keeping her condition sharp with sword training as she had done in her past life.

After learning the ways of a healer and convincing the elf village that she is capable enough of leaving for the outside world, she hitched a ride with a party of adventurers passing by the village and went out to see how the world has changed.

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

The brash Li Chengfeng makes a living through trickery with his clueless but loyal servant, Xiaobao. One day, the love of his life is murdered, making him a suspect, and he meets a demon who suspects he is the reincarnation of a traitorous immortal.

When the natural disasters come, the whole people travel through the wasteland world and face the challenge of death and survival!

Horrible acid rain, monstrous floods, sky-burning cities, global glaciers, super radiation…

No one is immune!

To survive, human beings can only build shelters and accept rounds of baptisms of natural disasters.

Fortunately, Somo awakened the doomsday survival system!

His refuge can be upgraded infinitely!

【Wooden Door】→【Iron Door】→【Alloy Gate】→…..

【Wooden Spear】→【Literwood Spear】→【Electromagnetic Spear】→…..

【Diesel generator】→【Bio generator】→【Thermoelectric generator】→…..

When everyone was rushing to prepare for the next disaster, Somo was already fully equipped and rampaged through the wasteland world.

“We’re still lighting the oil lamp, and they all use the refrigerator!”

“His refuge is said that the walls are tens of meters thick and it is the safest place in the world.”

“In my lifetime, I want to live in the Sushen Refuge for one day”

- Description from novelbuddy